The present invention relates to a projector that projects an image formed on an image display device, such as a liquid crystal panel, via a projection lens, and particularly relates to a technique of simplifying adjustments made to projection conditions of the projector.
In recent years, so-called xe2x80x9clight-valve typexe2x80x9d projectors have come into widespread use. A light-valve type projector forms an image on a light valve, such as a liquid crystal panel, and projects the image onto a screen via a projection lens.
When such a conventional projector is set in a space, such as a hall, the procedure shown as the flowchart in FIG. 1 has been employed.
As shown in FIG. 1, the setting procedure for a projector 200 (see FIG. 2) is roughly divided into two stages. One stage is for the preliminary setting of the projector 200 (steps S501 to S504), and this stage is referred to as the xe2x80x9csimulationxe2x80x9d. The other stage is for the actual setting of the projector 200 at the site (steps S505 to S510), and setup and adjustments of the projector 200 are performed in this stage.
In the simulation, a size of an image to be projected by the projector 200 (this size is referred to as the xe2x80x9cprojection display sizexe2x80x9d hereinafter) is first set (step S501). Then, a distance between a projection lens 210 of the projector 200 and a screen 300 (this distance is referred to as the xe2x80x9cprojection distancexe2x80x9d hereinafter) and a vertical positional relation between the projector 200 and the screen 300 are roughly set (step S502).
FIG. 2 and FIG. 3 are respectively a side view and a top plan view showing the positional relation between the projector 200 and the screen 300. In FIG. 2, a distance L1 indicates the projection distance measured between the screen 300 and the projection lens 210 of the projector 200. A distance L2 indicates the vertical relative distance between the screen 300 and the projector 200. The distance L2 is calculated by subtracting a distance between the vertical center of the projection lens 210 and the floor from a distance between the vertical center of the screen 300 and the floor.
As to the projection distance L1 and the vertical relative distance L2, a user refers to specifications of a plurality of projection lenses prepared for the projector 200 and roughly sets these distances with consideration given to various conditions, such as space, of the setting site.
Based on the results of the above rough settings, an appropriate lens is selected from the plurality of projection lenses prepared for the projector 200 (step S503). Selecting the optimum lens largely depends on the zoom ratio of the projection lens 210 and the availability of the zoom function.
When the projection lens having the zoom function is selected as the projection lens 210, the zoom ratio is set and an amount of vertical axis displacement adjustment is roughly calculated.
Here, the amount of vertical axis displacement adjustment refers to an amount by which the position of the light valve is adjusted relative to the optical axis of the projection lens 210 in the vertical direction. This adjustment is made so that a projection position of an image coincides with the correct position of the screen 300 in the vertical direction. The amount of vertical axis displacement is easily obtained from the zoom ratio and the vertical relative distance L2 between the screen 300 and the projector 200 that was calculated in step S502.
When this amount of vertical axis displacement exceeds the maximum amount described in the specifications of the projector 200, a support table 250 is set under the projector 200 to make up an insufficient height (step S504). Accordingly, the rough simulation based on the specifications of the projector 200 is completed.
Next, the setup and adjustments of the projector 200 performed in accordance with the stated rough simulation is explained.
First, based on the results of the simulation, the position of the projector 200 to be set at the site is determined (step S505). Here, the setting position of the projector 200 should be determined with a high degree of precision in accordance with the projection distance obtained in the simulation. Also, the setting direction of the projector 200 and the positional relation between the projector 200 and the screen 300 should be adjusted at a high degree of precision. To be more specific regarding the positional relation, the setting direction of the projector 200 should be adjusted so as to be parallel to the direction of the normal to the screen 300 in the horizontal direction, while it should be adjusted in the vertical direction so as to correspond to a predetermined setting angle as specified for the projector 200.
After the projector 200 has been accordingly positioned, the projector 200 is turned on and an image actually projected onto the screen 300 is assessed. In general, the projection distance is rechecked by actual measurement in a case where the adjustment performance for the projected images is highly valued (step S506).
When the setting position of the projector 200 is judged to be imperfect from the assessment of the image projected on the screen 300 and actual measurement of the projection distance (xe2x80x9cNGxe2x80x9d in step S506), the processing returns to step S505 to reset the position of the projector 200. On the other hand, when the setting position of the projector 200 is judged to have no problems from the assessment of the image projected on the screen 300 and actual measurement of the projection distance (xe2x80x9cOKxe2x80x9d in step S506), the processing advances to step S507. When the projection lens 210 is a zoom-type lens, adjustment to the zoom ratio of the projection lens, the so-called xe2x80x9czoom adjustmentxe2x80x9d, is performed (step S507). Following this, adjustment to the vertical axis displacement of the projection lens 210 is performed (step S508). Then, the focus of the projection lens 210 is adjusted (step S509).
The zoom adjustment, vertical axis displacement adjustment, and focus adjustment are not completely independent of one another. Therefore, the user has to execute these adjustments as necessary while viewing the image projected on the screen 300. More specifically, if the zoom ratio is changed, the amounts of axis displacement and focus adjustments will also vary and so have to be accordingly adjusted. While making fine adjustments, the user reassesses the image projected on the screen 300. If the projection state resulting from the fine adjustments is judged to be inadequate, the zoom ratio, axis displacement, and focus adjustments are repeated so as to converge on an optimum projection state.
After these adjustments have been completed, it is confirmed that the projection display size, geometric distortion, and consistency in the focus performance for the entire display area satisfy a level required for the current use of the projector 200 (step S510). If there are still problems in the projection conditions of the projector 200 in this stage of confirming the adjustment results (xe2x80x9cNGxe2x80x9d in step S510), the processing returns to step S505 to reset the position of the projector 200. Then, the fine adjustments to the position of the projector 200 and readjustments to the projection lens system are repeated. When the image quality is judged to be adequate to the level required for the current use of the projector 200 (xe2x80x9cOKxe2x80x9d in step S510), the projector setting including the setup and adjustments is terminated.
For the conventional projector, the adjustments to the projection lens are electrically controlled in order to help simplify the adjustments to the projector. FIG. 4 shows a construction example of a driving system that is provided for such a conventional projector to drive the projection lens.
As shown in FIG. 4, the driving system of the projection lens 210 is composed of a focus driving unit 211, a zoom driving unit 212, a vertical axis displacement adjusting mechanism 213, and a vertical axis displacement driving unit 214. The focus driving unit 211 electrically drives a focus adjusting mechanism of the projection lens 210. The zoom driving unit 212 electrically drives a zoom adjusting mechanism. The vertical axis displacement adjusting mechanism 213 holds the projection lens 210 in such a manner that the projection lens 210 can shift in the vertical direction, and executes the vertical axis displacement adjustment. The vertical axis displacement driving unit 214 electrically drives the vertical axis displacement adjusting mechanism 213.
A control unit that controls the driving system of the projection lens 210 is composed of a remote controller 201, a controller signal photoreceiver 202, a controller signal decoding circuit 203, a microcomputer 205, and a data memory 206.
A control operation of the projector 200 is explained, taking a case where the focus adjustment is performed using the driving system of the projection lens 210 as an example. The user makes key entries using the remote controller 201 while checking the current state of the focus adjustment made to an image projected on the screen 300. Controller signals based on the key operation by the user are transmitted in the form of infrared ray signals or the like from the remote controller 201 to the controller signal photoreceiver 202.
The controller signal photoreceiver 202 converts the signals transmitted in the form of infrared ray signals or the like into analog electric signals. The analog electric signals are decoded into digital signals by the controller signal decoding circuit 203, and are inputted to the microcomputer 205.
The microcomputer 205 outputs a focus control signal based on the inputted controller signal information to the focus driving unit 211.
In accordance with the focus control signal received from the microcomputer 205, the focus driving unit 211 changes the focus state of the image projected on the screen 300 by driving the focus adjusting mechanism of the projection lens 210. The user assesses the change in the focus state of the projected image resulting from the key operation. If the projected image is judged to have no problems, the user sets the current state as the optimum focus state using the remote controller 201. Subsequent to this, adjustment data indicating the optimum focus state is stored in the nonvolatile data memory 206 according to the instruction from the remote controller 201.
When the zoom driving unit 212 and the vertical axis displacement driving unit 214 are driven and controlled to make the adjustments to the zoom and axis displacement, the same signal control and series of operations using the remote controller 201 are performed as is the case with the stated focus adjustment.
However, the adjustments made to the setting position of the projector and to the zoom ratio, focus, and axis displacement of the projection lens have to be performed based on the combination of the visual assessment of the projected image and manual adjustments to the positions of the projector and the projection lens, in accordance with the projection conditions and specifications of the projection lens. On top of that, these -adjustments have to be repeated to converge on the optimum projection state for the projector and the screen. Thus, this conventional method has problems of a time taken for the adjustments, adjustment precision, and a rise in the cost of the adjustment technique. To reduce these problems, the projection conditions have to be set at a high degree of precision (within a precision of a few centimeters) in the simulation stage. This also takes much time.
These circumstances remain the same even though the projection lens system is electrically driven and so the adjustments are simplified as compared with the manual adjustments. In spite of this improvement, the user has to adjust each component independently based on the visual assessment of the projected image. In order to converge on the optimum condition, the user still has to execute the adjustments at much expense in time and effort.
Particularly, there are market requirements in recent years, such as a bigger screen size, higher brightness, higher definition, longer focuses for the projection distance in a particular use, and capability for use in an emergency. These requirements are increasingly rising especially for oversize high-brightness projectors. An oversize high-brightness projector is heavy, meaning that it is not easy to set the projector at a site. When this projector is to be set under a strict setting condition, such as suspending the projector from a ceiling of a large hall, it is considerably hard to repeat the above-mentioned adjustments.
In general, the projection lens of the high-brightness projector can be selected from a plurality of lenses, such as fixed-focus type and zoom type lenses. The projection conditions are different for each lens type, and therefore it further takes time to converge on the optimum projection state.
It is therefore an object of the present invention to provide a projector which can be easily set up and adjusted to an optimum state particularly when the projector is used in a large space, such as a hall.
The projector of the present invention is made up of: a lens driving unit for driving the projection lens; a receiving unit for receiving an input of at least one projection condition; a parameter determining unit for determining a control parameter to control the lens driving unit, in accordance with the received projection condition; and a control unit for controlling the lens driving unit in accordance with the determined control parameter.
With this construction, the control parameter is automatically determined in accordance with the projection condition received by the receiving unit. Based on the determined control parameter, the lens driving unit is driven. Consequently, the user can quickly set and adjust the projector without the inconvenience of manually adjusting the setting position of the projector.
When the projection lens to be used in the projector is interchangeable, the control parameter can be determined in accordance with the selected projection lens and projection condition that were received as the projection conditions by the receiving unit.
The projector is also made up of: a storing unit for storing information regarding a characteristic for each of a plurality of interchangeable projection lenses; a selecting unit, in accordance with the information stored in the storing unit, for selecting a projection lens from the plurality of projections lenses as an optimum projection lens, the characteristic of the selected projection lens most satisfying the received projection condition; and a displaying unit for indicating the projection lens selected as the optimum projection lens. With this construction, the user will not hesitate over which projection lens to select.
The projector of the present invention is made up of: a receiving unit for receiving an input from a user; a control unit for controlling the lens driving unit in accordance with the input received from the user; a pattern generating unit for displaying a predetermined pattern formed from a plurality of pattern images on the image display device so that the plurality of pattern images are respectively displayed at a plurality of positions on a display area of the image display device; a calculating unit for calculating errors in setting conditions of the projector in accordance with amounts of control to be performed by the control unit for each pattern image through an input operation which the user performed to adjust a projection state of the pattern image projected on the screen; and a displaying unit for indicating the errors calculated by the calculating unit.
By means of this construction, the user can obtain the errors in the setting conditions of the projector simply by adjusting each projection state of the pattern images, thereby easily performing the high-precision adjustments to the setting conditions of the projector.
The projector is also made up of: an entry screen displaying unit for displaying an entry screen on which the user inputs a content that is to be received by the receiving unit; and an entry screen control unit for having the entry screen show the content that is received by the receiving unit from the user. Thus, the user can extremely easily perform the adjustments by referring to the content displayed on the entry screen.